src/Environment/fgclouds.cxx

   1 // Build a cloud layer based on metar
   2 //
   3 // Written by Harald JOHNSEN, started April 2005.
   4 //
   5 // Copyright (C) 2005  Harald JOHNSEN - hjohnsen@evc.net
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20 //
  21 //
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include "config.h"
  25 #endif
  26
  27 #include <cstring>
  28 #include <cstdio>
  29 #include <Main/fg_props.hxx>
  30
  31 #include <simgear/constants.h>
  32 #include <simgear/sound/soundmgr_openal.hxx>
  33 #include <simgear/scene/sky/sky.hxx>
  34 //#include <simgear/environment/visual_enviro.hxx>
  35 #include <simgear/scene/sky/cloudfield.hxx>
  36 #include <simgear/scene/sky/newcloud.hxx>
  37 #include <simgear/structure/commands.hxx>
  38 #include <simgear/props/props_io.hxx>
  39
  40 #include <Main/globals.hxx>
  41 #include <Main/util.hxx>
  42 #include <Viewer/renderer.hxx>
  43 #include <Airports/simple.hxx>
  44
  45 #include "fgclouds.hxx"
  46
  47 static bool do_delete_3Dcloud (const SGPropertyNode *arg);
  48 static bool do_move_3Dcloud (const SGPropertyNode *arg);
  49 static bool do_add_3Dcloud (const SGPropertyNode *arg);
  50
  51 // RNG seed to ensure cloud synchronization across multi-process
  52 // deployments
  53 static mt seed;
  54
  55 FGClouds::FGClouds() :
  56 #if 0
  57     snd_lightning(0),
  58 #endif
  59     clouds_3d_enabled(false),
  60     index(0)
  61 {
  62         update_event = 0;
  63 }
  64
  65 FGClouds::~FGClouds()
  66 {
  67 }
  68
  69 int FGClouds::get_update_event(void) const {
  70         return update_event;
  71 }
  72
  73 void FGClouds::set_update_event(int count) {
  74         update_event = count;
  75         buildCloudLayers();
  76 }
  77
  78 void FGClouds::Init(void) {
  79 #if 0
  80         if( snd_lightning == NULL ) {
  81                 snd_lightning = new SGSoundSample("Sounds/thunder.wav", SGPath());
  82                 snd_lightning->set_max_dist(7000.0f);
  83                 snd_lightning->set_reference_dist(3000.0f);
  84                 SGSoundMgr *smgr = globals->get_soundmgr();
  85                 SGSampleGroup *sgr = smgr->find("weather", true);
  86                 sgr->add( snd_lightning, "thunder" );
  87         }
  88 #endif
  89
  90         mt_init_time_10(&seed);
  91
  92         globals->get_commands()->addCommand("add-cloud", do_add_3Dcloud);
  93         globals->get_commands()->addCommand("del-cloud", do_delete_3Dcloud);
  94         globals->get_commands()->addCommand("move-cloud", do_move_3Dcloud);
  95 }
  96
  97 // Build an invidual cloud. Returns the extents of the cloud for coverage calculations
  98 double FGClouds::buildCloud(SGPropertyNode *cloud_def_root, SGPropertyNode *box_def_root, const string& name, double grid_z_rand, SGCloudField *layer) {
  99         SGPropertyNode *box_def=NULL;
 100         SGPropertyNode *cld_def=NULL;
 101         double extent = 0.0;
 102
 103         SGPath texture_root = globals->get_fg_root();
 104         texture_root.append("Textures");
 105         texture_root.append("Sky");
 106
 107         box_def = box_def_root->getChild(name.c_str());
 108
 109         string base_name = name.substr(0,2);
 110         if( !box_def ) {
 111                 if( name[2] == '-' ) {
 112                         box_def = box_def_root->getChild(base_name.c_str());
 113                 }
 114                 if( !box_def )
 115                         return 0.0;
 116         }
 117
 118         double x = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 119         double y = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 120         double z = grid_z_rand * (mt_rand(&seed) - 0.5);
 121
 122         float lon = fgGetNode("/position/longitude-deg", false)->getFloatValue();
 123         float lat = fgGetNode("/position/latitude-deg", false)->getFloatValue();
 124
 125         SGVec3f pos(x,y,z);
 126
 127         for(int i = 0; i < box_def->nChildren() ; i++) {
 128                 SGPropertyNode *abox = box_def->getChild(i);
 129                 if( strcmp(abox->getName(), "box") == 0) {
 130
 131                         string type = abox->getStringValue("type", "cu-small");
 132                         cld_def = cloud_def_root->getChild(type.c_str());
 133                         if ( !cld_def ) return 0.0;
 134
 135                         double w = abox->getDoubleValue("width", 1000.0);
 136                         double h = abox->getDoubleValue("height", 1000.0);
 137                         int hdist = abox->getIntValue("hdist", 1);
 138                         int vdist = abox->getIntValue("vdist", 1);
 139
 140                         double c = abox->getDoubleValue("count", 5);
 141                         int count = (int) (c + (mt_rand(&seed) - 0.5) * c);
 142
 143                         extent = std::max(w*w, extent);
 144
 145                         for (int j = 0; j < count; j++) {
 146
 147                                 // Locate the clouds randomly in the defined space. The hdist and
 148                                 // vdist values control the horizontal and vertical distribution
 149                                 // by simply summing random components.
 150                                 double x = 0.0;
 151                                 double y = 0.0;
 152                                 double z = 0.0;
 153
 154                                 for (int k = 0; k < hdist; k++)
 155                                 {
 156                                         x += (mt_rand(&seed) / hdist);
 157                                         y += (mt_rand(&seed) / hdist);
 158                                 }
 159
 160                                 for (int k = 0; k < vdist; k++)
 161                                 {
 162                                         z += (mt_rand(&seed) / vdist);
 163                                 }
 164
 165                                 x = w * (x - 0.5) + pos[0]; // N/S
 166                                 y = w * (y - 0.5) + pos[1]; // E/W
 167                                 z = h * z + pos[2]; // Up/Down. pos[2] is the cloudbase
 168
 169                                 //SGVec3f newpos = SGVec3f(x, y, z);
 170                                 SGNewCloud cld(texture_root, cld_def, &seed);
 171
 172                                 //layer->addCloud(newpos, cld.genCloud());
 173                                 layer->addCloud(lon, lat, z, x, y, index++, cld.genCloud());
 174                         }
 175                 }
 176         }
 177
 178         // Return the maximum extent of the cloud
 179         return extent;
 180 }
 181
 182 void FGClouds::buildLayer(int iLayer, const string& name, double coverage) {
 183         struct {
 184                 string name;
 185                 double count;
 186         } tCloudVariety[20];
 187         int CloudVarietyCount = 0;
 188         double totalCount = 0.0;
 189
 190     SGSky* thesky = globals->get_renderer()->getSky();
 191
 192         SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 193         SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 194         SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
 195         SGCloudField *layer = thesky->get_cloud_layer(iLayer)->get_layer3D();
 196         layer->clear();
 197
 198         // If we don't have the required properties, then render the cloud in 2D
 199         if ((! clouds_3d_enabled) || coverage == 0.0 ||
 200                 layer_def_root == NULL || cloud_def_root == NULL || box_def_root == NULL) {
 201                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 202                         return;
 203         }
 204
 205         // If we can't find a definition for this cloud type, then render the cloud in 2D
 206         SGPropertyNode *layer_def=NULL;
 207         layer_def = layer_def_root->getChild(name.c_str());
 208         if( !layer_def ) {
 209                 if( name[2] == '-' ) {
 210                         string base_name = name.substr(0,2);
 211                         layer_def = layer_def_root->getChild(base_name.c_str());
 212                 }
 213                 if( !layer_def ) {
 214                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 215                         return;
 216                 }
 217         }
 218
 219         // At this point, we know we've got some 3D clouds to generate.
 220         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(true);
 221
 222         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 223
 224         for(int i = 0; i < layer_def->nChildren() ; i++) {
 225                 SGPropertyNode *acloud = layer_def->getChild(i);
 226                 if( strcmp(acloud->getName(), "cloud") == 0) {
 227                         string cloud_name = acloud->getStringValue("name");
 228                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 229                         double count = acloud->getDoubleValue("count", 1.0);
 230                         tCloudVariety[CloudVarietyCount].count = count;
 231                         int variety = 0;
 232                         cloud_name = cloud_name + "-%d";
 233                         char variety_name[50];
 234                         do {
 235                                 variety++;
 236                                 snprintf(variety_name, sizeof(variety_name) - 1, cloud_name.c_str(), variety);
 237                         } while( box_def_root->getChild(variety_name, 0, false) );
 238
 239                         totalCount += count;
 240                         if( CloudVarietyCount < 20 )
 241                                 CloudVarietyCount++;
 242                 }
 243         }
 244         totalCount = 1.0 / totalCount;
 245
 246         // Determine how much cloud coverage we need in m^2.
 247         double cov = coverage * SGCloudField::fieldSize * SGCloudField::fieldSize;
 248
 249         while (cov > 0.0f) {
 250                 double choice = mt_rand(&seed);
 251
 252                 for(int i = 0; i < CloudVarietyCount ; i ++) {
 253                         choice -= tCloudVariety[i].count * totalCount;
 254                         if( choice <= 0.0 ) {
 255                                 cov -= buildCloud(cloud_def_root,
 256                                                 box_def_root,
 257                                                 tCloudVariety[i].name,
 258                                                 grid_z_rand,
 259                                                 layer);
 260                                 break;
 261                         }
 262                 }
 263         }
 264
 265         // Now we've built any clouds, enable them and set the density (coverage)
 266         //layer->setCoverage(coverage);
 267         //layer->applyCoverage();
 268         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(clouds_3d_enabled);
 269 }
 270
 271 void FGClouds::buildCloudLayers(void) {
 272         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 273
 274         //double wind_speed_kt   = metar_root->getDoubleValue("wind-speed-kt");
 275         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 276         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 277         double pressure_mb       = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 278         double rel_humidity      = metar_root->getDoubleValue("relative-humidity");
 279
 280         // formule d'Epsy, base d'un cumulus
 281         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 282         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 283
 284     SGSky* thesky = globals->get_renderer()->getSky();
 285         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 286                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 287
 288                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 289                 double alt_m = alt_ft * SG_FEET_TO_METER;
 290                 string coverage = cloud_root->getStringValue("coverage");
 291
 292                 double coverage_norm = 0.0;
 293                 if( coverage == "few" )
 294                         coverage_norm = 2.0/8.0;        // <1-2
 295                 else if( coverage == "scattered" )
 296                         coverage_norm = 4.0/8.0;        // 3-4
 297                 else if( coverage == "broken" )
 298                         coverage_norm = 6.0/8.0;        // 5-7
 299                 else if( coverage == "overcast" )
 300                         coverage_norm = 8.0/8.0;        // 8
 301
 302                 string layer_type = "nn";
 303
 304                 if( coverage == "cirrus" ) {
 305                         layer_type = "ci";
 306                 } else if( alt_ft > 16500 ) {
 307 //                      layer_type = "ci|cs|cc";
 308                         layer_type = "ci";
 309                 } else if( alt_ft > 6500 ) {
 310 //                      layer_type = "as|ac|ns";
 311                         layer_type = "ac";
 312                         if( pressure_mb < 1005.0 && coverage_norm >= 0.5 )
 313                                 layer_type = "ns";
 314                 } else {
 315 //                      layer_type = "st|cu|cb|sc";
 316                         if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m ) {
 317                                 // +/- 20% from cumulus probable base
 318                                 layer_type = "cu";
 319                         } else if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m ) {
 320                                 // +/- 20% from stratus probable base
 321                                 layer_type = "st";
 322                         } else {
 323                                 // above formulae is far from perfect
 324                                 if ( alt_ft < 2000 )
 325                                         layer_type = "st";
 326                                 else if( alt_ft < 4500 )
 327                                         layer_type = "cu";
 328                                 else
 329                                         layer_type = "sc";
 330                         }
 331                 }
 332
 333                 cloud_root->setStringValue("layer-type",layer_type);
 334                 buildLayer(iLayer, layer_type, coverage_norm);
 335         }
 336 }
 337
 338 void FGClouds::set_3dClouds(bool enable)
 339 {
 340         if (enable != clouds_3d_enabled) {
 341                 clouds_3d_enabled = enable;
 342                 buildCloudLayers();
 343         }
 344 }
 345
 346 bool FGClouds::get_3dClouds() const
 347 {
 348         return clouds_3d_enabled;
 349 }
 350
 351 /**
 352  * Adds a 3D cloud to a cloud layer.
 353  *
 354  * Property arguments
 355  * layer - the layer index to add this cloud to. (Defaults to 0)
 356  * index - the index for this cloud (to be used later)
 357  * lon/lat/alt - the position for the cloud
 358  * (Various) - cloud definition properties. See README.3DClouds
 359  *
 360  */
 361  static bool
 362  do_add_3Dcloud (const SGPropertyNode *arg)
 363  {
 364    int l = arg->getIntValue("layer", 0);
 365    int index = arg->getIntValue("index", 0);
 366
 367    SGPath texture_root = globals->get_fg_root();
 368          texture_root.append("Textures");
 369          texture_root.append("Sky");
 370
 371          float lon = arg->getFloatValue("lon-deg", 0.0f);
 372          float lat = arg->getFloatValue("lat-deg", 0.0f);
 373          float alt = arg->getFloatValue("alt-ft",  0.0f);
 374          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 375          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 376
 377    SGSky* thesky = globals->get_renderer()->getSky();
 378    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 379    SGNewCloud cld(texture_root, arg, &seed);
 380    bool success = layer->addCloud(lon, lat, alt, x, y, index, cld.genCloud());
 381
 382    // Adding a 3D cloud immediately makes this layer 3D.
 383    thesky->get_cloud_layer(l)->set_enable3dClouds(true);
 384
 385    return success;
 386  }
 387
 388  /**
 389   * Removes a 3D cloud from a cloud layer
 390   *
 391   * Property arguments
 392   *
 393   * layer - the layer index to remove this cloud from. (defaults to 0)
 394   * index - the cloud index
 395   *
 396   */
 397  static bool
 398  do_delete_3Dcloud (const SGPropertyNode *arg)
 399  {
 400    int l = arg->getIntValue("layer", 0);
 401    int i = arg->getIntValue("index", 0);
 402
 403    SGSky* thesky = globals->get_renderer()->getSky();
 404    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 405          return layer->deleteCloud(i);
 406  }
 407
 408 /**
 409  * Move a cloud within a 3D layer
 410  *
 411  * Property arguments
 412  * layer - the layer index to add this cloud to. (Defaults to 0)
 413  * index - the cloud index to move.
 414  * lon/lat/alt - the position for the cloud
 415  *
 416  */
 417  static bool
 418  do_move_3Dcloud (const SGPropertyNode *arg)
 419  {
 420    int l = arg->getIntValue("layer", 0);
 421    int i = arg->getIntValue("index", 0);
 422       SGSky* thesky = globals->get_renderer()->getSky();
 423
 424          float lon = arg->getFloatValue("lon-deg", 0.0f);
 425          float lat = arg->getFloatValue("lat-deg", 0.0f);
 426          float alt = arg->getFloatValue("alt-ft",  0.0f);
 427          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 428          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 429
 430    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 431          return layer->repositionCloud(i, lon, lat, alt, x, y);
 432  }